Natarajan et al. in U.S. patent applications Ser. No. 400,798 filed July 22, 1982 and Ser. No. 513,931 filed July 14, 1983 discloses acylalkylaminocarbonyl substituted amino and imino acid compounds of the formula ##STR2## These compounds are disclosed as possessing angiotensin converting enzyme inhibition activity and in some cases, depending upon the definition of X, also possessing enkephalinase inhibition activity.